The Beltrami County Sheriff’s Office says a loud boom shook a large part of Bemidji and much of the neighboring areas Monday evening.

According to the Sheriff’s Office, reports came in around 6:40 p.m. of a loud explosion after a bright blue and white flash in the sky.

After looking at power substations and transformers, authorities shared the incident on social media, saying they then learned the flash was heard and the boom was heard over not only much of southern Beltrami County, but also neighboring counties.

A Nymore resident captured the incident on a security camera, and additional video from the Bemidji Regional Airport showed an object appearing to streak across the frame. However, authorities said it is undetermined whether the two videos are related.

There was speculation from the Sheriff’s Office that a meteor passed over, but that theory is seemingly unlikely.

Authorities sent the video from the airport to a scientist at NASA, who determined that the object was too horizontal to be a meteor and that more data needed to be collected to further eliminate possible other interfering objects.

Authorities haven’t found any damage in the area, or recovered any objects.

“This has certainly been an interesting puzzle to try and solve, and we still don’t know exactly what it was,“ said Christopher Muller, Beltrami County Emergency Management Director and Public Information Officer.  “We appreciate the assistance we’ve received from federal agencies and science community in ruling out what it wasn’t and will continue to provide any subsequent information that is learned.” 

“The fact this was seen and heard across such a large area is what is a mystery,” he continued. “What was it?” 

The flash and the boom were calculated to have occurred less than a mile apart, according to the Sheriff’s Office. It is currently unknown whether the source of the flash and boom was stationary or mobile.

Witnesses reported seeing the flash over an area of around 50 miles, and the boom could be heard from even farther away, authorities said. It was loud enough to rattle windows, shake houses and set car alarms off.

The Beltrami County Sheriff’s Office said that unless there is a significant development, there will not be any further updates.